Apparatus for oxidizing ore.



No. 672,065. Patented Apr. 16, 190i. H. c. LAWRENCE.

APPARATUS FOR OXIDIZING ORE.

(Application filed Man 17, 1900 2 Sheets-Sheet l.

(No Modei.)

No. 672,065. Patented Apr. l6, lam; u. c. LAWRENCE.

APPARATUS FOR OXIDIZING ORE.

(Applicafion filed mal l'l, 1900.)

(NoModeL) 2 Sheets-Sheet 2.

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UNITED STATES PATENT OFFICE.

HENRY C. LAWRENCE, OF DENVER, COLORADO, ASSIGNOR OF TWO-THIRDS TO W. B.PUTNAM AND ROLAND E. BRUNER, OF KANSAS CITY, MISSOURI.

APPARATUS FOR OX-IDIZING ORE.

SPECIFICATION forming part of Letters Patent N 0. 672,065, dated April16, 1901.

Application filed March 17, 1900. Serial No. 9,129. (No model.)

To all whom it may concern:

Be itknown that I, HENRY O. LAWRENCE, a citizen of the United States,residing at Denver, in the county of Arapahoe, in the State of Colorado,have invented certain new and useful Improvements in Ore-OxidizingApparatus, of which the following is afull, clear, and exactdescription, reference being had to the accompanying drawings, whichform a IO part of this specification:

My invention relates to apparatus for reducing mineral ores by oxidationand taking care of the mineral and by-products carried over with thecombustion and oxidizing vapors and gases; and myinvention consists incertain features of novelty hereinafter described, and pointed out inthe claims.

Figure 1 represents a side elevation of my improved apparatus. Fig. 2represents alongitudinal section showing the throat of the furnace andits connection with the oxidizingdrum. Fig. 3 represents a verticalsection of the separating-chamber for separating the mineral andby-products of oxidation that may be carried over from the vapors, takenon the line X X of Fig. 1. Fig. 4 represents a vertical section on theline X X of Fig. 3. Fig. 5 represents, in partial cross-section, thetank for washing the vapors and gases in passage from theseparating-chamber back to the furnace. Fig. 6 represents a detailcrosssection of the throat of the furnace with the casing omitted. Fig.7 represents a crosssection showing the communication between 5 theoxidizing-drum and the precipitatingchamber. Fig. 8 represents across-section of the discharge-pipe, showing the damper and screentherein.

Similar numerals refer to similar parts throughout the several views.

1 represents an oxidizingdru m formed with an outer metallic casing 2and a lining of firebrick orlike refractory material3. Said drum isprovided with the circumferential tracks 4,

5 arranged to travel on the flanged wheels 5, mounted upon the standards6, the mounting being such that the feed end of the drum is slightlyhigher than the discharge end, thus providing for the travel of thematerial through the drum.

7 represents a series of sprocket teeth mounted upon the drum, asprocket-chain 8, engaging said teeth, and a sprocket-wheel 9 on a shaft10,,mounted on the standards 11. A cone-pulley 12 is mounted on saidshaft 10, belted to any convenient source of power, and thereby a motionof revolution given to the drum, which may readily be accelerated ordiminished by adjustment of the belt on the cone-pulleys. 6o

14 represents a furnace having a restricted throat 15. In said throatisseated the smaller end of a cone-shaped casing 16, extending a distanceforward into the furnace and provided with openings 17 in its lowerside, the purpose of the said casing being to collect and concentratethe heat from the furnace at the discharge-opening of the throat 15.Said casing may, however, be omitted when solid fuel is used, the samebeing designed more particularly for use when liquid or gaseous fuel isemployed. Said furnace communicates with the oxidizing-drum 1 throughthe conical passage 18, which expands toward the drum, the wall formingsaid passage entering a short distance and fitting closely within thedrum, but not so as to interfere with the revolution of the drum.

19 represents a pipe passing through the furnace and through the casing16 to the throat 15 and connected with a steam-boiler, (not shown,) orthe steam may be generated in a coil of water-pipes 19, arranged in thefurnace and connected with a source of water-supply and with thesteam-pipe 19. The steam passing through said pipe is super heated andunder pressure is discharged at a high velocity at the throat 15, andthus acts in the nature of an injector to generate a strong draft to thefurnace and into the drum 0 through the passage 18.

The ore is fed from the chute 20 through the screw conveyor 21, thescrew forming a force feed and preventing clogging of the ore. Saidscrew is operated by the cone-pulleys 22, whereby the feed may beregulated as may be desired, and is thus automatic and continuous. Theconveyer 21 discharges into the passage 18 from the furnace directly atits entrance into the drum, so that the ore immeroo diately upon itsdischarge is subjected to the oxidizing action of the blast from thefurnace and continues subject thereto until the discharge at theopposite end of the drum of the unvolatilized oxidized product throughthe chute 23 into the ore-bin 24, from which it may be removed by meansof the usual conveyer or otherwise, as maybe desired. In practice it isfound prudent that the chute 23 should extend somewhat below the line ofthe ore in the bin 24 to prevent the escape and dissemination of thevapors and fumes which might otherwise pass down through the chute.

25 represents a separating or precipitating chamber communicating withthe oxidizingdrum through the passage 26, the drum extending into saidpassage such distance and fitting sufficiently close as to prevent theescape of the vapors and fumes without interfering with the action ofthe drum. Said precipitating-chamber is provided on its sides with thewater-jackets 27 and on its interior with a series of hollow shelves 28,communicating alternately with the water-jackets on the opposite sidesand providing alternately on opposite sides the passages 29 for thepassage of the vapors and volatilized oxids through the chamber. Toprovide for the circulation of the water from the water-jackets throughsaid shelves 28, as well as through the water-jackets, medial plates 30are mounted therein, the water being admitted through the pipe 31 anddischarged through the pipe 32, said pipes being provided with thestopcocks 33 and 34. By the circulation of the water the shelves arecooled and the vapors in passage coming in contact therewith are cooled,so that the volatilized oxids and other mineral products carried overare precipitated upon the shelves, whence they may be removed by drawingout through the doors 35, whence they will fall through the chute 36into an ore-bin 37. A discharge-pipe 38 from said separating-chamberleads to the smokestack or outer atmosphere. Said pipe is provided witha damper 39, hinged at one side to the pipe, as shown at 40, andarranged to close upon and to be supported by an annular flange orbracket 41, secured upon the pipe. Said damper may be provided with ahandle 42, by which the same may be operated, if desired. A screen 43,of line wire-gauze, is also provided in said pipe to obstruct thepassage of any solid matter that may not have been precipitated in thecircuitous passage through the chamber. Said screen may, if desired, beconstructed of gunny-cloth or like material, the vapors and other matterhaving been cooled off by contact with the cooling-shelves to suchextent as to prevent any danger of setting fire to the screen.

44 represents a return-pipe communicating with said discharge-pipe 38between said damper and said screen and leading back to the furnace anddischarging therein through the pipe 45 under the grate-bars, so thatthe returned gases shall pass up through the fuel or through the pipe 46over the fuel, said pipes being provided with dampers 47 and 48, so thateither one or both thereof may be used, as desired. In said return-pipe44 is interposed a tank 49, containing water and provided with aperforated intermediate bottom 50 immediately above the line of theinlet and outlet of said pipe. A pump 51 is provided for pumping thewater from the lower to the upper part of the tank, which is thencesprayed through said perforated bottom, and thereby the sulfuric acidformed in the oxidizing process and carried over with the gases iswashed out as the gases pass through the tank.

The weight of the damper 39 is such that under ordinary pressure in thedrum and precipitating-chamber the gases will pass through thereturn-pipe 44; but if from any cause there should be excessive pressuresaid damper will be raised, and acting as a safetyvalve such excessivepressure will be relieved and any danger therefrom is thus avoided.

In ordinary treatment the length of the drum and the inclination andrapidity of rotation are such that the ore from its entrance into thedrum until its discharge therefrom is subjected to the oxidizing actionfor about two hours; but. this may of course be varied by a differentinclination of the drum 01' by a more or less rapid rotation, as may bedesired, or as may be required from the nature ofthe ore to be treated.

Among the more important advantages gained by the use of this apparatusmay be noted:

First. The operation is continuous, it not being necessary to stop toremove the contents of the drum and recharge the same.

Second. By the injector action ofthe steamjet, arranged in the narrowthroat of the furnace, the heat of combustion of the combustion productsgenerated in the furnace is not confined to and wasted in the furnace,but is carried directly into the drum and there utilized, the furnaceacting merely as a generator to free the combustion products from thefuel.

Third. The widening of the passage between the furnace and the drumpermits the expansion and sudden inflammation of the gases, and the orebeing fed at this point is subject, immediately as it enters, to theintense heat generated and the oxidizing influence thereof.

Fourth. The ore as it travels through the drum is subjected to aconstantly-increasing temperature and consequent greater oxidizingaction.

Fifth. The volatilized oxidized products and other valuable by-productspassing over with the vapor and fumes from the drum and which wouldotherwise be wasted are recovered by contact with the cooling-shelves inthe precipitating-chamber.

Sixth. The sudden cooling by contact with the cooling-shelves preventsrecombination evaoes of the gases, so that very little, if any,noncombustible gases are formed and returned to the furnace.

Seventh. The sulfuric acid recovered as a by-product is in the treatmentof ores containing sulfur more than sufficient to pay the runningexpenses of the apparatus.

Having thus fully described my improvements, what I claim as myinvention, and desire to secure by Letters Patent, is

1. In an ore-oxidizing apparatus the combination with a furnace, arotating ore-drum, a passage communicating between said furnace and saiddrum, and a feed-chute communicating with said passage, of a conicalcasing arranged in the furnace and having its smaller end seated in saidpassage, and a steam-pipe extending into and terminating in said casing,whereby an injector-blast is delivered upon the ore as it is fed intosaid passage; substantially as set forth.

2. In an ore-oxidizing apparatus the combination with a furnace, arotating ore-drum, and a passage communicating between said furnace andsaid drum, of a conical casing arranged in the furnace and havingitssmaller end seated in said passage, and a steam-pipe mounted in andarranged to be heated by the furnace, extending into and terminatingnear the end of said casing, whereby an injectorblast is provided fromsaid furnace into said drum; substantially as set forth.

3. In an ore-oxidizing apparatus the combination with a furnace, and arotating oredrum communicating with said furnace through a suitablepassage, of a conical casing arranged in the furnace and having itssmaller end seated in said passage, and a steam-pipe extending into saidcasing whereby is formed an injector-blast from said furnace into saiddrum; substantially as set forth.

4. In an ore-oxidizing apparatus, a precipi taling-chamber,hollowshelves,provided with interior circulating-plates, mounted in saidchamber, and arranged to provide a circuitous passage for the vaporsand'gases through said chamber, and inlet and oulet passagescommunicating with said hollow shelves for providing circulation throughthe same; substantially as set forth.

5. In an ore oxidizing apparatus a water-jacketed precipitating-chamber,hollow shelves mounted in said chamber communicating with thewater-jacket thereof and arranged to provide a circuitous passage forthe vapors and gases through said chamber, plates mounted in said hollowshelves and arranged to provide for the circulation of the water throughthe same, and valved inlet and outlet pipes, communicating with saidwaterjacket for controlling the circulation of the water through thesaid jacket and said shelves; substantially as set forth.

6. In an ore oxidizing apparatus, a wator-jacketedprecipitating-chamber, hollow shelves provided with circulatingplatesmounted in said chamber communicating with said water-jacket andarranged to provide a circuitous passage for the vapors and gasesthrough said chamber, doors to said chamber for the removal of theprecipitated products from said shelves, a chute mounted on the outerwall of said chamber for conveyin g the removed product to a suitablereceptacle and valved pipes communicating with said water-jacketsubstantially as set forth.

7. In an ore-oxidizing apparatus the combi nation with a rotatingore-drum, a furnace communicating with said drum, and aprecipitating-cha mber communicating with said drum, of a return-pipecommunicating with said chamber and leading back to the furnace abovethe grate, and a pipe communicating with said return-pipe and with thefurnace under the grate; substantially as set forth.

8. In an ore-oxidizing apparatus, the combination with a rotatingore-drum and a furnace communicating with said drum, of aprecipitating-chamber communicating with said drum, a discharge-pipe forconveying the vapors and gases from said chamber, a damper hinged insaid dischargepipe, a bracket mounted in said discharge-pipe forsupporting said damper when closed, and a return-pipe communicating withsaid discharge-pipe below said damper and with the furnace;substantially as set forth.

9. In an ore-oxidizing apparatus, the combination with a rotatingore-drum, a furnace communicating with said drum, and aprecipitating-chamber communicating with said drum, of a return-pipecommunicating with said chamber and with the furnace, a tank containingwater interposed in the line of said return pipe, and a perforated platemounted in said tank above the line of the inlet and outlet of saidpipe, whereby the water is sprayed over the returning vapors and gasesfor the removal of the soluble gases therefrom; substantially as setforth.

10. In an ore-oxidizing apparatus, the combination with a rotatingore-drum, of a furnace having a contracted throat, a conical casinghaving its smaller end seated in said contracted throat, and providedwith openings on its lower side, and a steam-pipe entering said throatand forming therein an injector for conveying the combustion gases intosaid drum, and a passage communicating between said furnace and saiddrum, said passage being contracted at its inlet to correspond with saidcontracted throat of the furnace, and thence enlarging or expandingtoward the drum; substantially as set forth.

HENRY O. LAWRENCE.

Witnesses:

J. A. HAYS, D. L. OSBORN.

